20 Examples of Catalysts (and their functions)
Miscellanea / / November 13, 2021
For catalyst you understand one substance or elementboth simple and compound, which plays an accelerating role in a chemical reaction determined, shortening the times in which it occurs but without altering the final product at all and without losing its own mass in the process (which does occur in reagents). For example: enzymes, UV light, zinc, cobalt.
This process of acceleration of a chemical reaction is called "catalysis". And the elements or substances that inhibit catalysis are known as inhibitors. Many chemical reactions need a suitable catalyst depending on whether you want to increase or decrease the rate at which they occur. In this sense, catalysis can be positive (the speed of the reaction increases) or negative (the speed of the reaction decreases).
The investigation in catalysis and production of catalytic agents is a prolific field of chemical and biological industry, since they allow to accelerate reactions simply with the opportune addition of the suitable catalyst.
Examples of catalyst (and its function)
- Enzymes. They are substances biologically and naturally secreted by the body of the living beings. Enzymes play a very important catalytic role, since they accelerate vital chemical processes that, if they occurred on their own, would require temperatures often incompatible with life. Pepsin and trypsin, for example, are involved in the breakdown of meats, speeding up digestion that would otherwise take much more time and effort.
- UV light. Ultraviolet light, together with a catalyst, enables photocatalysis: the acceleration of a chemical reaction by the work of a catalyst activated by the light energy of ultraviolet. Ozone and metal oxides transition are common photocatalysts.
- Palladium catalysts. Built into automobile systems that use unleaded gasoline, these devices contain Palladium or platinum in small particles in a container that adheres to the exhausts of the automobiles. These metals act as catalysts in the process of attenuation of carbon monoxide and other toxic gases of the combustion, and allow them to be reduced to water vapor or other less dangerous substances in record time.
- Aluminum chloride. This catalyst is used in the petrochemical industry to obtain synthetic resins or lubricating substances, without altering the delicate nature of the hydrocarbons in question, since it has acidic and basic properties at the same time (it is amphoteric).
- Fluorine derivatives. They accelerate the decomposition of ozone (O3 → O + O2), which is normally a fairly slow reaction. This is the problem of aerosols and refrigerants that release CFCs into the atmosphere: they dilute the ozone layer.
- Acidic substances. The protons released by most of the acidic substances can play the role of catalysts in certain chemical reactions, such as hydrolysis (the breakdown of esters to form carboxylic acids and alcohols) of esters (organic petroleum derivatives).
- Zinc. It is a common catalyst in the constitution of cycloalkanes (saturated hydrocarbons) used in perfumery, the oil industry and others.
- Manganese dioxide (MnO2). This compound is a frequent catalyst to accelerate the decomposition of hydrogen peroxide or hydrogen peroxide (2H2O2 → 2H2O + O2).
- Iron (III). East metal It is used as a catalyst in the Haber-Bosch process to obtain ammonia from hydrogen and nitrogen.
- Vanadium pentoxide (V2OR5). It is a highly toxic compound that reversibly loses oxygen when heated. That is why it is used as a catalyst in obtaining sulfuric acid from sulfur dioxide (SO2).
- Titanium. Mixed with aluminum, it is used in the Ziegler-Natta polymerization process to accelerate the obtaining high-density polyethylene (HDPE), used to manufacture containers and bottle caps plastic.
- Nickel. Finely divided, it is used in the hydrogenation of vegetable oils through which margarine is obtained: fats unsaturated become saturated by bombardment of hydrogen and this metal accelerates this process.
- Silicon dioxide or silica (SO2). It is one of the most widely used catalysts in the oil catalytic cracking process, in addition to high pressure and temperatures. The cracking It consists of obtaining simpler substances from a complex hydrocarbon.
- Cobalt (Co) and Molybdenum (Mo). They are substances used on alumina in the catalytic reforming process of petroleum, in which heavy naphtha is separated from sulfur and nitrogen, to increase its octane number.
- Potassium permanganate (KMnO4). It is used as a catalyst for the chemical reaction that transforms alkenes (unsaturated hydrocarbons or olefins) into diols.
- Platinum. This metal is used as a catalyst in certain reactions to obtain benzene derivatives, such as cyclohexane, essential in the manufacture of nylon.
- Gold. Recent research shows the effectiveness of gold as a nanocatalyst, that is, when it is found in atomic groups of between eight and two dozen atoms.
- Citric acid. The acid contained in lemon or other citrus fruits slows down (negative catalysis) the process of oxidation from organic material. This can be verified with a piece of apple.
- Silver. Polycrystalline silver and nanoporous silver in electrocatalysis experiments are effective accelerators of the carbon dioxide (CO2) reduction processes, which allow the efficient production of chemical products tools.
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